**Prepare the Vegetables:** Slice the cucumbers and red onion thinly and place them in a large mixing bowl.
**Make the Dressing:** In a small bowl, whisk together Greek yogurt (or sour cream), olive oil, lemon juice, garlic powder, and 1 tablespoon of the everything bagel seasoning. Season with salt and pepper to taste.
**Combine Salad:** Pour the dressing over the cucumbers and onions. Add the chopped dill and toss until the vegetables are evenly coated.
**Finish with Seasoning:** Sprinkle the remaining everything bagel seasoning on top before serving.
**Chill (Optional):** For best flavor, let the salad sit in the refrigerator for 15–20 minutes before serving.